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. 2022 Feb 4:41:107926.
doi: 10.1016/j.dib.2022.107926. eCollection 2022 Apr.

Data on phenylalanine-to-tyrosine ratios in assessment of tetrahydrobiopterin (BH4)-responsiveness in patients with hyperphenylalaninemia

Barbka Repic Lampret  1 , Mojca Zerjav Tansek  2   3 , Blaz Groselj  3   4 , Jaka Sikonja  3 , Tadej Battelino  2   3 , Urh Groselj  2   3
Affiliations

Data on phenylalanine-to-tyrosine ratios in assessment of tetrahydrobiopterin (BH4)-responsiveness in patients with hyperphenylalaninemia

Barbka Repic Lampret et al. Data Brief. .

Abstract

Blood phenylalanine-to-tyrosine (Phe/Tyr) ratio is an important indicator of metabolic control in phenylketonuria patients. We present the data that highlights the role of Phe/Tyr-ratio in the evaluation of tetrahydrobiopterin (BH4)-responsiveness in patients with hyperphenylalaninemia. Our data complements the results from the original research article by Tansek et al., 2012 [1]. We performed a BH4-loading test in 32 patients after four days of increased protein intake (2000 mg/kg body weight). Blood sampling was performed 96, 72, 48, 24, 16 h, and moments before oral administration of BH4 in a dose of 20 mg/kg body weight. Additional blood samples were collected 8 and 24 h after its administration. Phenylalanine (Phe) and Tyrosine (Tyr) levels were determined from dried blood spots by tandem mass spectrometry. Phe/Tyr-ratio reached a plateau after three days of increased dietary protein intake. Fifteen patients (47%) responded to BH4, defined as a decrease of Phe-of at least 30% after 24 h of BH4 administration. Phe/Tyr-ratios were significantly higher in non-responders compared to responders. In the responder group, Phe/Tyr-ratios decreased in average of 67% (p = 0.001) and 45% (p = 0.001) after 8 and 24 h of BH4 administration, respectively. Phe/Tyr-ratio decreased after 8 h of drug administration also in the non-responder group, but not 24 h after administration.

Keywords: BH4, tetrahydrobiopterin; BH4-responsiveness; F, female; Hyperphenylalaninemia; M, male; MHP, mild hyperphenylalaninemia; NI, not included; NR, non-responder; Phe, phenylalanine; Phe/Tyr-ratio, phenylalanine-to-tyrosine ratio; Phenylalanine-to-tyrosine ratio; Phenylketonuria; R, responder; Tandem mass spectrometry; Tetrahydrobiopterin; Tyr, tyrosine; cPKU, classic phenylketonuria; mPKU, mild phenylketonuria.

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Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.the authors declare the following financial interests/personal relationships which may be considered as potential competing interests:

Figures

Image, graphical abstract
Graphical abstract
Fig 1
Fig. 1
Phe/Tyr-ratios and Tyr-concentrations prior to BH4 administration.
Fig 2
Fig. 2
Phe/Tyr-ratios and Tyr-concentrations across different metabolic phenotypes.
Fig 3
Fig. 3
Phe/Tyr-ratios and BH4-responsiveness.
Fig 4
Fig. 4
Study protocol and blood samples collection.
See this image and copyright information in PMC

References

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